(R) Mandatory Non-Medical Switching Policy from Originator to Biosimilar Infliximab in Patients with Inflammatory Bowel Disease in British Columbia: A Cohort Study

Friday, August 26, 2022

8:00 AM – 6:00 PM CEST

Location: Hall E South

Publication Number: 308

Presenting Author(s)

Anat Fisher, MD, PhD
– Rsearch Associate, University of British Columbia, University of British Columbia, Vancouver, British Columbia, Canada

Co-Author(s)

Jason D. Kim
– University of British Columbia, Canada
Colin Dormuth
– University of British Columbia, Victoria, British Columbia, Canada

Background: On September 5th, 2019, British Columbia’s public drug plan program changed its coverage policy to switch patients treated with originator infliximab for inflammatory bowel diseases (IBD) to an infliximab biosimilar.

Objectives: To monitor the impacts of the British Columbia policy on health services utilization during the first year of the policy.

Methods: We conducted a population-based cohort study using administrative data from British Columbia. We constructed 3 historical cohorts and 1 policy cohort of users of originator infliximab with IBD. We excluded users not covered by the provincial drug plan. We monitored the cumulative incidence of prescription refills for immunomodulatory drugs, switching to other biologic medications, and the use of additional health services. Log-likelihood ratios were used to quantify differences between the policy cohort and the average of the historical cohorts.

Results: The market share of biosimilars increased among patients with IBD during the first year of the policy: from 10% to 82% of infliximab prescriptions in adults, and from 1% to 97% in children. The cohorts included 1839–2368 users of infliximab originator, ages 4–90 years, mean age 43 years. The major findings during the first year of follow-up were: (1) a 0.9% increase in refilling infliximab, biosimilar or originator; (2) a 16% increase in dose escalation; (3) decreases of 2.4% in antibiotic filling and 2.6% in prednisone use; (4) an anticipated increase in visits to physicians and gastroenterologists to manage switching to biosimilars (24%); (5) a 4% decrease in discharge from hospital; and (6) a 3% decrease in emergency admission to hospital.

Conclusions: The results of the present study suggest British Columbia’s Biosimilars Initiative for non-medical switching from originator to biosimilar infliximab for IBD was not associated with increased health services utilization, which served also as proxies for patient health. An increase in dose escalation was accompanied by an improvement in health status proxies.